Suppose you purchase a 30-year, zero-coupon bond with a yield to maturity of 8%. You hold the bond for five years before selling it.

a. If the bond's yield to maturity is 8% when you sell it, what is the internal rate of return of your investment?

b. If the bond's yield to maturity is 9% when you sell it, what is the internal rate of return of your investment?

c. If the bond's yield to maturity is 7% when you sell it, what is the internal rate of return of your investment?

d. Even if a bond has no chance of default, is your investment risk free if you plan to sell it before it matures? Explain. Note: Assume annual compounding.